WO2012169524A1

WO2012169524A1 - Underrun protector structure

Info

Publication number: WO2012169524A1
Application number: PCT/JP2012/064550
Authority: WO
Inventors: 尚彦井口
Original assignee: いすゞ自動車株式会社
Priority date: 2011-06-09
Filing date: 2012-06-06
Publication date: 2012-12-13
Also published as: JP5796770B2; JP2012254738A

Abstract

An underrun protector structure (3) has: a front underrun protector (hereinafter, referred to as an FUP) (5); a stay bracket (6) which supports the FUP (5); an energy absorber (7) which is pressed in the front-back direction by an absorber pressing portion (14) of the FUP (5); and a step fixed portion bracket (8) which supports the back of the energy absorber (7). An extension portion (13) of the FUP (5) is provided with a folding portion (16) which is an easy extending portion (15) formed by folding a part of the extension portion (13) in the front-back direction. When an impactor (9) collides against a vehicle (1), the absorber pressing portion (14) of the FUP (5) is about to move backward, and tension load acts on the extension portion (13) of the FUP (5), the folding portion (16) expands to allow the absorber pressing portion (14) to move backward.

Description

Underrun protector structure

The present invention relates to the structure of the underrun protector.

In Japanese Patent Laid-Open No. 11-255050, a protector bracket and a step fixing member for a boarding / alighting step are respectively fixed to side surfaces of a chassis frame, and a portion near the center of the front underrun protector is supported by the protector bracket, and the front under An under-run protector structure is described in which an energy absorption type coupling member is installed between the end portion of the run protector and the step fixing member.

JP 11-255050 A

In the conventional structure described above, the center portion of the front underrun protector is firmly supported by the chassis frame by the protector bracket, so at the time of an offset collision in which another vehicle collides with the end of the front underrun protector, the front The end side of the front underrun protector moves rearward while the rearward movement of the portion near the center of the underrun protector is restricted. At this time, a tensile load that acts diagonally rearward on the outer side in the vehicle width direction acts on the end portion side of the front underrun protector, and a reaction force that opposes the tensile load is provided between the central portion and the end portion. Occurs diagonally forward in the vehicle width direction. The component of the reaction force in the front-rear direction (component force toward the front) acts as a load on other vehicles, and the component in the vehicle width direction (component force toward the inside in the vehicle width direction) acts as a shearing force on the coupling member. To do. For this reason, if the collision load increases and an excessive reaction force is generated, the load acting on the other vehicle also becomes excessive, and the impact received by the other vehicle may not be sufficiently mitigated. Further, when the shearing force acting on the coupling member is increased, the coupling member is bent, and the deformation of the coupling member in the front-rear direction becomes insufficient, which may cause a decrease in energy absorption.

The present invention has been made in view of the above-described actual situation, and is capable of suitably mitigating an impact received by another vehicle at the time of an offset collision and capable of suppressing a decrease in energy absorption. The purpose is to provide a protector structure.

In order to achieve the above object, the underrun protector structure of the present invention includes an underrun protector, a stay bracket, and an energy absorber. The underrun protector includes an absorber pressing portion on the outer end side in the vehicle width direction, a protruding portion on the inner side in the vehicle width direction from the absorber pressing portion, and a supported portion on the inner side in the vehicle width direction from the protruding portion. The vehicle body frame extends in the vehicle width direction below the front or rear end of the vehicle body frame. The stay bracket is fixed to the vehicle body frame and supports the supported portion of the underrun protector. The energy absorber is supported by the vehicle body frame behind or in front of the absorber pressing portion of the underrun protector and is pressed by the absorber pressing portion that moves backward or forward due to a vehicle collision to absorb the collision energy. The overhanging portion of the underrun protector has an easily extending portion that extends when a tensile load acts on the overhanging portion and allows the absorber pressing portion to move backward or forward.

In the above configuration, since the supported portion of the vehicle underrun protector is firmly supported by the body frame by the stay bracket, at the time of an offset collision in which another vehicle collides with the absorber pressing portion of the underrun protector from the front or the rear. The absorber pressing portion of the under-run protector moves rearward or forward in a state where movement of the supported portion of the under-run protector to the rear or front is restricted. At this time, a tensile load directed diagonally backward or forward on the outer side in the vehicle width direction acts on the absorber pressing portion and the overhang portion of the underrun protector. When this tensile load increases, the easy extension part extends and allows the absorber pressing part to move backward or forward. Since the extension of the easy extension portion suppresses the generation of reaction force against the tensile load, the reaction force acting on other energy components and the reaction force acting as a shear force on the energy absorber. The generation of the component force in the vehicle width direction is also suppressed. Therefore, an increase in the load acting on the other vehicle is suppressed, and the impact received by the other vehicle can be suitably mitigated. Moreover, the fall of the energy absorption amount resulting from the bending of an energy absorber can be suppressed.

Further, the easy extension part of the underrun protector is a folding part that is formed by folding back a part of the overhanging part in a direction crossing the vehicle width direction, and expands when a tensile load acts on the overhanging part. Also good.

In the above configuration, when the tensile load on the diagonally rearward or forward side on the vehicle width direction acting on the absorber pressing portion and the overhanging portion of the underrun protector increases, the folding portion expands to expand, and the absorber pressing portion Allow backward or forward movement. For this reason, increase of the load which acts on another vehicle is suppressed, the impact which another vehicle receives can be relieve | moderated suitably, and the fall of energy absorption amount can be suppressed.

Also, since the folding part is formed integrally with the underrun protector, the number of parts is not increased with a simple structure, and an increase in cost can be suppressed.

The underrun protector is divided into a first protector having a supported portion on the inner side in the vehicle width direction and a second protector having an absorber pressing portion on the outer side in the vehicle width direction, and is formed in the vehicle width direction of the second protector. The inner end portion is temporarily held by the first protector at an initial position overlapping the outer end portion of the first protector in the vehicle width direction, and slides outward in the vehicle width direction in a state where the temporary hold by the first protector is released. The easily extended portion of the underrun protector is supported by the first protector so that the temporary load is released from the outer end portion of the first protector when the tensile load is applied to the projecting portion and the temporary holding is released. It may be the inner end of the second protector that slides toward it.

In the above configuration, the tensile load toward the diagonally rearward or forward outside of the vehicle width direction acting on the absorber pressing portion and the overhanging portion of the second protector increases, and the first protector temporarily holds the inner end portion of the second protector. When is released, the inner end portion of the second protector slides toward the outside in the vehicle width direction from the initial position, and allows the absorber pressing portion to move backward or forward. For this reason, increase of the load which acts on another vehicle is suppressed, the impact which another vehicle receives can be relieve | moderated suitably, and the fall of energy absorption amount can be suppressed.

Further, since the easy extension part extends due to the sliding movement of the inner end part of the second protector, when the second protector is extended, the second protector is unlikely to have an uneven shape change in the front-rear direction. The smoothness of the front or rear surface of the protector is not easily lost. Therefore, variation in the vehicle width direction of the impact load input from the second protector to the other vehicle is suppressed, and a local increase in the impact load received by the other vehicle can be suppressed.

In the underrun protector structure, the underrun protector is a front underrun protector that extends in the vehicle width direction below the front end of the vehicle body, and is supported by a side portion of the vehicle body frame and moves up and down to the vehicle cab. The step fixing member which fixes the step for raising / lowering used as scaffolding of this may be provided, and a step fixing member may support an energy absorber from back.

In the above configuration, at the time of an offset collision in which another vehicle collides with the absorber pressing portion of the front underrun protector of the vehicle from the front, the absorber pressing portion moves rearward and presses the energy absorber. Since the energy absorber is supported rearward by the step fixing member, the energy absorber is crushed and deformed in the front-rear direction to absorb the impact energy, and the impact received by other vehicles can be suitably mitigated. In addition, since an existing step fixing member can be used for the vehicle to support the energy absorber, a special support structure is not required, and an increase in cost can be suppressed.

According to the present invention, it is possible to suitably mitigate an impact received by another vehicle at the time of a vehicle offset collision, and to suppress a decrease in energy absorption amount.

It is a model side view of the cab overtrack provided with the underrun protector structure concerning this invention. It is a model top view explaining the underrun protector structure concerning the 1st Embodiment of this invention. It is a schematic top view explaining a state when a collision occurs in the first embodiment. It is a model top view explaining the underrun protector structure concerning the 2nd Embodiment of this invention. It is a schematic top view explaining a state when a collision occurs in the second embodiment. It is a schematic side view of a cab overtrack when the present invention is applied to a rear underrun protector.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the figure, FR indicates the front of the vehicle, UP in the figure indicates the upper side of the vehicle, and IN in the figure indicates the inner side in the vehicle width direction. Further, in the following description, the front-rear direction means the front-rear direction of the vehicle, and the left-right direction means the left-right direction in a state of facing the front of the vehicle.

As shown in FIG. 1, a vehicle 1 according to the present embodiment is a cab-over type vehicle in which a cab 2 is positioned in front of an engine (not shown), and an underrun protector is disposed at the front of the vehicle 1. Structure 3 is provided. The underrun protector structure 3 is provided symmetrically on the left and right sides of the vehicle 1 and supports a common front underrun protector (underrun protector) 5 on the left and right. Since the left and right under-run protector structures 3 have substantially the same configuration, only the right side will be described below and the left side description will be omitted.

As shown in FIG. 2, the underrun protector structure 3 includes a main frame 4, a front underrun protector (underrun protector) 5, a stay bracket 6, an energy absorber 7, and a step fixing bracket (step fixing member). 8 and.
The main frame 4 extends in the vehicle front-rear direction on both sides of the vehicle 1 in the vehicle width direction, and the front end portions of the left and right main frames 4 are connected by a cross member 11.

The stay bracket 6 has a base portion 17 and a support portion 18. The base portion 17 is fixed to the front end portion of the main frame 4 and extends downward. The support portion 18 is joined to the lower front end portion of the base portion 17.

The front underrun protector (hereinafter referred to as FUP) 5 is formed in a plate shape, is fixed to the support portion 18 of the stay bracket 6 and extends in the vehicle width direction. The FUP 5 includes a bracket fixing portion (supported portion) 12 that is fixed to the stay bracket 6, an overhang portion 13 that extends outward in the vehicle width direction from the bracket fixing portion 12, and an absorber that is further outward in the vehicle width direction than the overhang portion 13. And a pressing portion 14. The overhanging portion 13 of the FUP 5 is integrally provided with a folding portion 16 to form an easily extending portion 15 (see FIG. 2). The folding part 16 has a first bent part 16a, a folded part 16b, and a second bent part 16c, and is formed in a substantially T-shape that extends rearward and intersects the vehicle width direction. That is, the FUP 5 extends from the bracket fixing portion 12 to the first bent portion 16a on the outer side in the vehicle width direction, bends substantially perpendicularly from the first bent portion 16a, and extends to the rear crossing the vehicle width direction. The second bent portion 16c is further bent at a substantially right angle and extended in the vehicle width direction. In the initial position before the collision body 9 such as another vehicle collides with the vehicle 1, the first bent portion 16a and the second bent portion 16c are in contact with each other. When the collision body 9 collides with the vehicle 1 and a tensile load acts on the overhanging portion 13 of the FUP 5, the folded portion 16b develops in a substantially V shape, and the first bent portion 16a and the second bent portion 16c are connected to the vehicle. The easy extension part 15 extends apart from each other in the width direction.

The step fixing bracket 8 has one end 8a fixed to the outer portion of the main frame 4, the other end 8b supporting the step 19 for lifting and lowering that functions as a scaffold when the occupant moves up and down to the cab 2, and one end 8a and the other end. An energy absorber fixing portion 8c for fixing the energy absorber 7 formed between the two and 8b is integrally provided. The step fixing bracket 8 extends outward in the vehicle width direction from one end 8a to the other end 8b, bends and extends downward, bends again, and extends outward in the vehicle width direction.

The energy absorber 7 includes a rectangular cylindrical main body 20 that opens in front and rear, a front plate 21 that closes the front opening, and a rear plate 22 that closes the rear opening. The front surface of the front plate 21 is fixed to the rear surface of the absorber pressing portion 14 of the FUP 5, and the rear surface of the rear plate 22 is fixed to the energy absorber fixing portion 8 c of the step fixing bracket 8. Since the energy absorber 7 is supported on the vehicle body side via the step fixing bracket 8 and its rearward movement is restricted, when an impact load is input from the front of the energy absorber 7, the main body 20 is crushed and deformed in the front-rear direction. The impact energy that is raised and input to the energy absorber 7 is efficiently absorbed.

In the present embodiment, as shown in FIG. 2, before the collision body 9 collides with the front surface of the vehicle 1, the folding portion 16 that is the easy extension portion 15 provided in the overhang portion 13 of the FUP 5 is substantially T-shaped. The first bent portion 16a and the second bent portion 16c of the folding portion 16 are in contact with each other.

When an offset collision occurs in which the collision body 9 collides from the front toward the end of the vehicle 1 and the collision body 9 comes into contact with the absorber pressing portion 14 of the FUP 5, the rearward movement of the bracket fixing portion 12 is restricted. In this state, the absorber pressing portion 14 moves rearward and presses the energy absorber 7. At this time, a tensile load directed diagonally rearward on the outer side in the vehicle width direction acts on the absorber pressing portion 14 and the overhang portion 13. When this tensile load increases, as shown in FIG. 3, the folded portion 16b of the folding portion 16 which is the easy extension portion 15 provided in the overhanging portion develops in a substantially V shape, and the first bent portion 16a and the first bent portion 16a The two bend portions 16c are separated from each other in the vehicle width direction, and the easy extension portion 15 is extended to allow the absorber pressing portion 14 to move backward. The extension of the easily extending portion 15 suppresses generation of a reaction force that is directed diagonally forward on the inner side in the vehicle width direction against the tensile load, and therefore the component force and energy of the reaction force acting on the collision body 9 that are directed forward in the front-rear direction. Occurrence of the reaction force acting on the absorber 7 as a shearing force and the component force toward the inner side in the vehicle width direction is also suppressed. Therefore, an increase in the load acting on the collision body 9 is suppressed, and the impact received by the collision body 9 can be suitably mitigated. In addition, a decrease in the amount of energy absorption due to the bending of the energy absorber 7 can be suppressed.

Further, since the folding part 16 is formed integrally with the FUP 5, the number of parts is not increased with a simple structure, and an increase in cost can be suppressed.

Moreover, since the energy absorber 7 is supported by the main frame 4 via the step fixing bracket 8 for fixing the step 19, a special mechanism for supporting the energy absorber 7 on the side of the vehicle body is required. do not do. Therefore, an existing step fixing bracket or the like can be used, and an increase in cost can be suppressed.

Next, a second embodiment of the present invention will be described based on the drawings. As shown in FIG. 4, the underrun protector structure 3 includes a main frame 4, a front underrun protector (underrun protector) 23, a stay bracket 6, an energy absorber 7, and a step fixing bracket 8. ing. Since the left and right under-run protector structures 3 have substantially the same configuration, the right side will be described below and the left side description will be omitted. Further, since the main frame 4, the stay bracket 6, the energy absorber 7, and the step fixing bracket 8 are the same as those in the first embodiment, the same reference numerals are given and the description thereof is omitted.

The front underrun protector (hereinafter referred to as FUP) 23 is divided and formed by a rectangular cylindrical first protector 24 and a plate-like second protector 25 and extends in the vehicle width direction. The inner diameters of the first protector 24 in the vertical direction and the front-rear direction are respectively larger than the plate width and plate thickness of the second protector 25 and are set so that the second protector 25 can be inserted inside the first protector 24. ing. The first protector 24 has a bracket fixing portion 26 (supported portion) fixed to the stay bracket 6 and a part of an overhanging portion 27 outside the bracket fixing portion 26 in the vehicle width direction. The second protector 25 has the other part of the overhang part 27 and the absorber pressing part 28 outside the overhang part 27 in the vehicle width direction. The inner end portion 25 a in the vehicle width direction of the second protector 25 is inserted into the outer end portion 24 a in the vehicle width direction of the first protector 24 to form an easily extending portion 29. In the second protector 25, the outer surface of the inner end portion 25a of the second protector 25 and the inner surface of the outer end portion 24a of the first protector 24 are temporarily held by the first protector by welding such as spot welding. The welding strength for temporary holding is such that when the collision body 9 collides with the vehicle 1, the absorber pressing portion 28 is pressed rearward, and a predetermined tensile load acts on the overhanging portion 27 of the FUP 23, the temporary holding is performed. It is set to be released. When the temporary holding is released, the inner end portion 25a of the second protector 25 slides outward in the vehicle width direction with the temporarily held position as an initial position, and the absorber pressing portion 28 of the FUP 23 moves backward. Allow.

The shape of the first protector 24 is not limited to the rectangular cylindrical shape as long as the inner end 25a of the second protector 25 is slidably supported, and has a substantially U-shaped cross section, a plate shape, or the like. Other shapes may be used.

In the present embodiment, as shown in FIG. 4, before the collision body 9 collides with the front surface of the vehicle 1, the inner end portion 25 a of the second protector 25 of the FUP 23 that is the easy extension portion 29 is the first protector 24. Temporarily held at the initial position inside the outer end 24a.

When an offset collision occurs in which the collision body 9 collides from the front to the end of the vehicle 1, the FUP 23 is in a state where the rearward movement of the bracket fixing portion 26 is restricted, and the absorber pressing portion 28 moves rearward and the energy is increased. The absorber 7 is pressed. At this time, a tensile load directed obliquely rearward on the outer side in the vehicle width direction acts on the absorber pressing portion 28 and the overhang portion 27. When the tensile load increases and exceeds the welding strength at which the outer end 24a of the first protector 24 and the inner end 25a of the second protector 25 are welded, temporary holding is released as shown in FIG. The inner end portion 25a of the second protector 25, which is the easily extending portion 29, slides from the initial position toward the outside in the vehicle width direction, allows the absorber pressing portion 28 to move backward, and resists the tensile load. Suppresses the generation of reaction force. Therefore, an increase in the load acting on the collision body 9 is suppressed, and the impact received by the collision body 9 can be suitably mitigated. In addition, a decrease in the amount of energy absorption due to the bending of the energy absorber 7 can be suppressed.

Further, since the easy extension part is extended by the sliding movement of the inner end part of the second protector 25, when the second protector 25 is extended, the shape of the uneven shape in the front-rear direction hardly occurs in the second protector 25. The smoothness of the front surface of the second protector 25 is not easily impaired. Therefore, variation in the vehicle width direction of the impact load input from the second protector 25 to the collision body 9 is suppressed, and a local increase in impact force received by the collision body 9 can be suppressed.

In addition, the

easy extension part

15 or 29 provided in the overhang |

projection part

13 or 27 of FUP5 or 23 is not limited to 1st Embodiment or 2nd Embodiment, The collision body 9 collides with the vehicle 1, and FUP The bellows structure may be any structure that extends when a tensile load is applied to the overhang portion and allows the FUP absorber pressing portion to move backward, such as a bellows structure having a plurality of turns in the front-rear direction or the up-down direction. May extend in the vehicle width direction and be formed on the overhanging portion of the FUP.

In the present embodiment, the rear surface of the rear plate 22 of the energy absorber 7 is supported by the step fixing bracket 8. However, the energy absorber 7 is supported by the pressure from the FUP

absorber pressing portion

14 or 28. Any structure that restricts the rearward movement of the energy absorber 7 may be used. For example, a support bracket or the like that is fixed to the side of the vehicle body frame may be separately provided to support the energy absorber 7.

Further, in this embodiment, the underrun protector structure 3 is applied to the

front underrun protector

5 or 23 disposed in front of the vehicle 1, but as shown in FIG. It is also possible to apply to the rear under-run protector 30 arranged on the lower side.

As mentioned above, although the embodiment to which the invention made by the present inventor is applied has been described, the present invention is not limited by the description and the drawings that form part of the disclosure of the present invention according to this embodiment. That is, it is needless to say that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

The present invention can be widely applied as an underrun protector structure for large vehicles such as cargo vehicles.

1 Vehicle 3 Under-run protector structure 4 Main frame (body frame)
5 Front underrun protector (underrun protector)
6 Stay bracket 7 Energy absorber 8 Step fixing bracket (Step fixing member)
9 Colliding body 12 Bracket fixing part (supported part)
13 Overhanging part 14 Absorber pressing part 15 Easy extension part
16 Folding part
19 Lifting step
23 Front underrun protector (underrun protector)
24 1st protector 24a The outer edge part of the vehicle width direction of a 1st protector
25 Second protector
25a Inner end of the second protector in the vehicle width direction
26 Bracket fixing part (supported part)
27 Overhanging part 28 Absorber pressing part 29 Easy extension part 30 Rear underrun protector (underrun protector)

Claims

An absorber pressing portion on the outer end side in the vehicle width direction, an overhang portion on the inner side in the vehicle width direction with respect to the absorber pressing portion, and a supported portion on the inner side in the vehicle width direction with respect to the overhang portion; An under-run protector extending in the vehicle width direction below the front or rear end of the vehicle body frame,
A stay bracket fixed to the vehicle body frame and supporting the supported portion of the underrun protector;
An energy absorber that is supported by the vehicle body frame behind or in front of the absorber pressing portion of the underrun protector and that is pressed by the absorber pressing portion that moves rearward or forward due to a collision of the vehicle and absorbs collision energy. The overhanging portion of the underrun protector has an easily extending portion that extends when a tensile load acts on the overhanging portion and allows the absorber pressing portion to move backward or forward. An under-run protector structure.
The underrun protector structure according to claim 1,
The easy extension part of the under-run protector is a folding part that is formed by folding back a part of the overhanging part in a direction crossing the vehicle width direction, and expands when a tensile load acts on the overhanging part. An underrun protector structure characterized by being.
The underrun protector structure according to claim 1,
The under-run protector is divided and formed into a first protector having the supported portion on the inner side in the vehicle width direction and a second protector having the absorber pressing portion on the outer side in the vehicle width direction,
The inner end portion of the second protector in the vehicle width direction is temporarily held by the first protector at an initial position overlapping the outer end portion of the first protector in the vehicle width direction, and is temporarily held by the first protector. In the released state, supported by the first protector so as to be slidable outward in the vehicle width direction,
The easy extension part of the underrun protector slides outward from the outer end part of the first protector in the vehicle width direction when a tensile load acts on the overhanging part and the temporary holding is released. The under-run protector structure is an inner end portion of the second protector.
The underrun protector structure according to claim 1, wherein:
The underrun protector is a front underrun protector that extends in the vehicle width direction below the front end of the vehicle body,
A step fixing member that is supported by a side portion of the vehicle body frame and fixes a step for raising and lowering that serves as a scaffold for an occupant to move up and down to the cab of the vehicle;
The step fixing member supports the energy absorber from behind. An underrun protector structure.